The Maier-Leibnitz-Laboratory for Nuclear and Particle Physics of LMU Munich and TU Munich

Nuclear Structure Studies at the MLL Tandem accelerator

Prof. Dr. Reiner Krücken TU Munich

Acting Director, MLL

QCD at shortest distances(elementary particles,

Hadron properties, SUSY, GUT)

QCD at large distances(Hadrons & Nuclei)

Applications of nuclear methods Material analysis

Medical applications & imagingRadiation biology

Neutrino propertiesDark matter

Electroweak interactions

Nuclear astrophysicsCosmology

Neutrino astronomy

Paul (TUM)Schaile (LMU)

Habs (LMU) Krücken (TUM)

Paul (TUM)

Habs (LMU) Krücken (TUM)

Paul (TUM)von Feilitzsch (TUM)

Paul (TUM)von Feilitzsch (TUM)

Habs (LMU)Krücken (TUM)

von Feilitzsch (TUM)

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tsBuras (TUM) Fritsch (LMU)Lüst (LMU)Ratz (TUM)

Ring (TUM) Weise (TUM) Wolter (LMU)

Buras (TUM) NN(TUM)

Mukhanov (LMU)Ring (TUM)

Theory

DFG Cluster of ExcellenceOrigin and Structure of the Universe

www.universe-cluster.de

MLL Tandem laboratory

14 MVTandem

Ion sources:- Polarized hydrogen- Sputter source- AMS source

MLL Tandem: Nuclear SpectroscopyQ3D: Light-ion transfer reactions with ~ 5 keV resolution - states in the 2nd and 3rd minimum in actinides - studies of single-particle structure

- discovery of multitude of 0+ states - investigation of cluster states

Electron conversion spectroscopy:- E0 strength in deformed nuclei- states in 2nd and 3rd minimum

MLL Trap (under construction):- mass measurements of highly charged ions- use of gas-ion-catcher- sympathetic cooling with laser cooled Mg+ ions- simultaneaous use of two precision traps- charge breeding with EBIS

final goal: m/m ≈ 10-10

Experimental search for 0+ states at Q3D

2005 (D.A. Meyer)

Plot by Ryan Winkler (Yale)

- (p,t) reactions - using 25 MeV protons- 3-5 angles

MLLUni KölnYaleBucharestSurrey

M. Csatlos et al., Phys. Lett. B 615 (2005) 175.

deep third minimum:

EIII = 2.7(4) MeV

rotational substructure of transmission resonances resolved in 235U(d,pf)236U, Ed= 10 MeV

rotational band fit of spectrum and angular distribution:

-> resonance is high-K hyperdeformed

Investigating the multiple-humped fission barrier in Actinides: 236U

Transmission resonances in prompt fission probability: coupling of compound states in 1. minimum to collective states in 2. and 3. minimum

P. Thirolf, D. Habs, A. Krasznahorkay (Debrecen)

MLL Tandem: MLL Trap Project

Increased 0+ density at the shape phase-transition

154Gd: D.A. Meyer et al., PLB 638 (2006), 44-49 and PRC 74 (2006) 044309

152Sm: D.A. Meyer, M. Reithner et al., to be published

Concept of the MLLTRAP Concept of the MLLTRAP facilityfacility

fusion reaction products from Tandem via buffer gas stopping cell (MLL-IonCatcher)

measurement with Penning trap of highly-charged ions

simultaneous relative measurement of individual ions in two precision traps

(sympathetic) cooling of highly-charged ions with laser-cooled Mg+ ions inside Penning trap and Paul trap

replacement of “classical” preparatory trap inside Penning set-up by A- and Z-selecting devices outside Penning trap

charge breeding with (commercial) EBIS

final goal: m/m ≈ 10-10

Physics: Q values for Vud MLL masses from radioactive beams GANIL (SPIRAL 2)